Cutting a Mono (dinghy) in half to make a cat

Getting back to the original idea of splitting an existing monohull boat or set of boat plans: I once considered splitting one of John Gardner's semi-dory designs, and stretching the stations to make a pair of 20' to 24' (6 or 7 meter) pontoons for an open-decked party boat with a canopy.

Seems to me the stretched semi-dory lines would drive easier than the usual party boat around herre. Their pontoons are typically just circular-section metal tubes, with clumsy-looking bows welded onto them.... They usually have large outboards, and shove an amazing amount of water out of the way when they're moving.